February 20, 2006

No Evidence of Bird-Flu Mutation in Indonesia

As noted in my previous post, the big concern about avian flu is not the current virus (which infects humans through infected birds), but a mutated virus that spreads from one human to another. Despite being around for several years, the current H5N1 virus has not undergone such a mutation. (And it is possible that a mutated H5N1 will also be less deadly to humans than the current, bird-based strain.)

An article in today'sWSJ [subscription req'd] confirms that no "pandemic" H5N1 strain has emerged:

There is no evidence that the bird-flu virus in Indonesia has mutated to a form that is readily transmissible among humans, the World Health Organization said, despite increasingly alarmed reports from Indonesian health officials.

Clusters of the disease among Indonesians may well indicate human exposure to the same sick birds, the WHO said, rather than the transmission of the disease from human to human, an event scientists fear could spark a pandemic.

"Should we be more worried? Not at this stage," Sari P. Setiogi, a spokeswoman for the WHO in Jakarta, said in an interview, adding that as health-care workers in the field become more aware of the disease, the number of reported cases may rise....In an article published in the Jakarta Post...last week, Anton Apriyantono, Indonesia's agriculture minister, was quoted as saying before a cabinet meeting, "The amount of time between contracting the virus and death is becoming shorter, raising the possibility the virus is becoming more virulent."

The WHO said it has found no evidence that this time frame is growing shorter. In 2005, the average length of illness in fatal human cases of bird flu was eight days, compared with 10 days in 2006, Ms. Setiogi said. "This does not suggest that the virus is becoming more virulent," she said.

Despite its relatively rapid spread to fowl around the world, WHO says that avian influenza has, to date, infected only 169 people in seven countries, and killed 91 of those infected. Since mid-2005, governments have grown increasingly aware of, and responsive to, the need to identify the virus in dead or sick birds, and to quarantine or destroy at-risk birds.